检索结果-南通市图书馆

Applied Mathematics and Mechanics(English Edition) 2025年第2期46卷 357-372页

作者： C.G.PAVITHRA b.j.GIREESHA S.SUSHMA K.j.GOWTHAM Department of PG Studies and Research in Mathematics Kuvempu University

A distinguished category of operational fluids, known as hybrid nanofluids,occupies a prominent role among various fluid types owing to its superior heat transfer properties. by employing a dovetail fin profile, this work investigates the thermal reaction of a dynamic fin system to a hybrid nanofluid with shape-based properties, flowing uniformly at a velocity U. The analysis focuses on four distinct types of nanoparticles,i.e., Al2O3, Ag, carbon nanotube (CNT), and graphene. Specifically, two of these particles exhibit a spherical shape, one possesses a cylindrical form, and the final type adopts a platelet morphology. The investigation delves into the pairing of these *** examination employs a combined approach to assess the constructional and thermal exchange characteristics of the hybrid nanofluid. The fin design, under the specified circumstances, gives rise to the derivation of a differential equation. The given equation is then transformed into a dimensionless form. Notably, the Hermite wavelet method is introduced for the first time to address the challenge posed by a moving fin submerged in a hybrid nanofluid with shape-dependent features. To validate the credibility of this research, the results obtained in this study are systematically compared with the numerical simulations. The examination discloses that the highest heat flux is achieved when combining nanoparticles with spherical and platelet shapes.

关键词： Hermite wavelet method radiation convection dovetail fin nanoparticle configuration O351.2

Integration of a hybrid vibration prediction model for railways into noise mapping software: methodology, assumptions and demonstration

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

RAILWAY ENGINEERING SCIENCE 2025年第1期33卷 1-26页

作者： Reumers, Pieter Degrande, Geert Lombaert, Geert Thompson, David j. Ntotsios, Evangelos bouvet, Pascal Nelain, brice Nuber, Andreas Katholieke Univ Leuven Dept Civil Engn Kasteelpk Arenberg 40 B-3001 Leuven Belgium Univ Southampton ISVR Southampton SO17 1BJ England Vibratec 28 Chemin Petit Bois F-69131 Ecully France Woelfel Engn GmbH Co K Max Planck Str 15 D-97204 Hoechberg Germany

Within the SILVARSTAR proj.ct, a user-friendly frequency-based hybrid prediction tool has been developed to assess the environmental impact of railway-induced vibration. This tool is integrated in existing noise mapping software. Following modern vibration standards and guidelines, the vibration velocity level in a building in each frequency band is expressed as the sum of a force density (source term), line source transfer mobility (propagation term) and building correction factor (receiver term). A hybrid approach is used that allows for a combination of experimental data and numerical predictions, providing increased flexibility and applicability. The train and track properties can be selected from a database or entered as numerical values. The user can select soil impedance and transfer functions from a database, pre-computed for a wide range of parameters with state-of-the-art models. An experimental database of force densities, transfer functions, free field vibration and input parameters is also provided. The building response is estimated by means of building correction factors. Assumptions within the modelling approach are made to reduce computation time but these can influence prediction accuracy;this is quantified for the case of a nominal intercity train running at different speeds on a ballasted track supported by homogeneous soil of varying stiffness. The paper focuses on the influence of these parameters on the compliance of the track-soil system and the free field response. We also demonstrate the use and discuss the validation of the vibration prediction tool for the case of a high-speed train running on a ballasted track in Lincent (belgium).

关键词： Railway-induced vibration Hybrid vibration prediction model Experimental validation Low-speed approximation

Atmospheric chemistry of trifluorodicarbonyls initiated by Cl atoms:Reactivity trends,mechanism,and acid formation yields

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Environmental Sciences 2025年第5期151卷 12-25页

作者： Pedro L.Lugo Vianni G.Straccia Cynthia b.Rivela Mariano A.Teruel María b.blanco Laboratorio Universitario de Química y Contaminación del Aire(L.U.Q.C.A) Instituto de Investigaciones en Fisicoquímica de Córdoba(I.N.F.I.Q.C.)Dpto.de Fisicoquímica.Facultad de Ciencias QuímicasUniversidad Nacional de Córdoba.Ciudad Universitaria5000 CórdobaArgentina Institute for Atmospheric and Environmental Research University of WuppertalDE-42097 WuppertalGermany

Rate coefficients of the gas-phase reactions of Cl atoms with a series of fluorinated diketones(FDKs):CF_(3)C(O)CH_(2)C(O)CH_(3)(TFP),CF_(3)C(O)CH_(2)C(O)CH_(2)CH_(3)(TFH)and CF_(3)C(O)CH_(2)C(O)CH(CH_(3))2(TFMH),have been measured at(298±2)K and under atmospheric *** experiments were performed using the relative-rate method with a GC-FID detection *** different determinations and references used,the following rate coefficients were obtained(in cm3/(molecule·sec)):k_(4)(TFP+Cl)=(1.75±0.21)×10^(−10),k_(5)(TFH+Cl)=(2.05±0.23)×10^(−10),k_(6)(TFMH+Cl)=(2.71±0.34)×10^(−10).Reactivity trends of FDKs were discussed and Free Energy Relationships analysis was *** expression lgkOH=1.68 lgkCl+5.71 was obtained for the reactivity of the studied FDKs together with similar unsaturated VOCs with Cl and OH radicals Additionally,acetic acid(CH_(3)C(O)OH)and trifluoroacetic acid(CF_(3)C(O)OH)were positively identified and quantified as degradation products using in situ FTIR *** to the identified products,atmospheric chemical mechanisms were *** atmospheric implications of the studied reactions were assessed by the estimation of the tropospheric lifetimes of TFP,TFH,and TFMH concerning their reaction with Cl atoms to be 48,41,and 31 hours,*** relatively short residence in the atmosphere of the fluorocarbons studied will have a local/regional impact with restricted *** warming potential(GWP(20 yr))calculated for the studied fluoro diketones were 0.014,0.003 and 0.001 for TFP,TFH and TFMH,respectively with a negligible contribution to the greenhouse effect.

关键词： Fluorinated diketones Kinetics SPME-GC-FID FTIR in situ SAR Free energy relationships

Clpb chaperone as a promising target for antimicrobial therapy: A narrative review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific j.urnal of Tropical biomedicine 2025年第1期15卷 1-10,I0001-I0007页

作者： Sachini j.Udari Sayoka Shamodhi Rumesh M.Nelumdeniya Udayana Ranatunga Nimesha N.Senadeera Chathuranga b.Ranaweera Department of Medical Laboratory Sciences Faculty of Allied Health SciencesGeneral Sir John Kotelawala Defence UniversityWerahera10718Sri Lanka Department of Pharmacy Faculty of Allied Health SciencesGeneral Sir John Kotelawala Defence UniversityWerahera10718Sri Lanka Department of Chemistry Faculty of ScienceUniversity of PeradeniyaPeradeniya20400Sri Lanka Department of Zoology and Environment Sciences Faculty of ScienceUniversity of ColomboColombo 0300300Sri Lanka

The Clp/Hsp100 family,part of the ATPase associated with various cellular activities(AAA+)superfamily,includes caseinolytic peptidase b(Clpb),a highly conserved protein found in bacteria,fungi,protozoa,and ***,Clpb is present in all ESKAPE pathogens:Enterococcus faecium,Staphylococcus aureus,Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa,and Enterobacter *** plays a crucial role in reactivating and disaggregating proteins,enabling pathogens to survive under host-induced stress and conferring thermotolerance to bacterial *** caused by ESKAPE pathogens are particularly challenging due to their resistance to broad-spectrum antibiotics and biofilm formation,posing a significant global health threat as they are often multidrug-resistant,extensively drug-resistant,and *** its absence in human cells and its essential role in bacterial survival under stress,Clpb is a promising target for antimicrobial *** Hsp100 family proteins could lead to the development of novel antifungal and antiprotozoal *** review explores the function of Clpb in the survival of ESKAPE pathogens and the protozoan Plasmodium *** research findings were compiled using academic databases,and data analysis was performed using Clustal Omega Multiple Sequence Alignment and boxshade tools.

关键词： Molecular chaperone Clpb ESKAPE pathogens Thermotolerance Heat shock proteins Plasmodium falciparum

Kinetics of the reaction of OH radical with ethylfluoroacetate,ethyl 4,4,4-trifluorobutyrate,and butylfluoroacetate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Environmental Sciences 2025年第5期151卷 273-283页

作者： Pedro L.Lugo Vianni Straccia Mariano A.Teruel María b.blanco Laboratorio Universitario de Química y Contaminación del Aire(L.U.Q.C.A) Institute for Research in Physical Chemistry of Córdoba(I.N.F.I.Q.C.)Department of Physical ChemistryFaculty of Chemical SciencesNational University of CórdobaUniversity CityCórdoba 5000Argentina Institute for Atmospheric and Environmental Research University of WuppertalWuppertal DE-42097Germany

Kinetics of the gas-phase reactions of•OH radicals with a series of fluoroesters were studied for the first time at 298±3 K and atmospheric *** rate coefficients were determined by in situ FTIR spectroscopy in nitrogen and GC-FID in air to monitor the decay of reactants and *** following coefficient values(in 10^(−12)cm^(3)/(molecule•sec))were obtained for ethyl fluoroacetate(EFA),ethyl 4,4,4-trifluorobutyrate(ETb),and butyl fluoroacetate(bFA),respectively:k_(1)(EFA+OH)=1.15±0.25 by FTIR and 1.34±0.23 by GC-FID;k_(2)(ETb+OH)=1.61±0.36 by FTIR and 2.02±0.30 by GC-FID;k_(3)(bFA+OH)=2.24±0.37 by *** trends were developed and correlated with the number of CH_(3)and F substituents in the fluoroester,and structure-activity relationships(SARs)calculations were *** addition,the tropospheric lifetimes of EFA,ETb,and bFA upon degradation by OH radicals were calculated to be 9,6,and 5 days,respectively,indicating that these fluorinated compounds could have a possible regional effect from the emission *** small photochemical ozone creation potentials of 9,7,and 19 were estimated for EFA,ETb,and bFA,*** GlobalWarming Potentials(GWPs)for EFA,ETb,and bFA were calculated for different time *** a 20-year time horizon,the GWPs were 1.393,0.063,and 0.062,*** the case of a 100-year time horizon,the GWPs were 0.379,0.017,and 0.017,and for a 500-year time horizon,the GWPs were 0.108,0.005,and 0.005 for EFA,ETb,and bFA.

关键词： CFC replacements sinks in situ FTIR SAR Acidification potentials Greenhouse gases

Hydrogen production from dry reforming of methane,using CO_(2)previously chemisorbed in the Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Environmental Sciences 2025年第3期149卷 535-550页

作者： Yocelin b.González-González Fernando Plascencia-Hernández Rubén Mendoza-Cruz Heriberto Pfeiffer Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de MéxicoCircuito exterior s/nCiudad UniversitariaDel.CoyoacánCP 04510CdMxMexico

Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was *** results were supported by XPS and TEM ***,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends ***,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni *** Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM *** demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane ***,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials.

关键词： Dry reforming of methane(DRM) CO_(2)chemisorption H_(2)production Solid solution Li_(6)ZnO_(4)

Plant-substrate biochar properties critical for mediating reductive debromination of 1,2-dibromoethane

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Environmental Sciences 2025年第1期147卷 1-10页

作者： j.nathan H.Lindhardt Peter E.Holm Yong-Guan Zhu Changyong Lu Hans Christian b.Hansen Department of Plant and Environmental Sciences Faculty of ScienceUniversity of CopenhagenThorvaldsensvej 401871 Frederiksberg CDenmark Key lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Sino-Danish Center for education and research China and DenmarkDalgas Avenue 4DK-8000 Aarhus C.Denmark

Dibromoethane is a widespread,persistent organic *** are known mediators of reductive dehalogenation by layered Fe^(Ⅱ)-Fe^(Ⅲ)hydroxides(green rust),which can reduce 1,2-dibromoethane to innocuous bromide and ***,the critical characteristics that determine mediator functionality are lesser *** biochar substrates were pyrolyzed at 600℃and 800℃,characterized by elemental analysis,X-ray photo spectrometry C and N surface speciation,X-ray powder diffraction,specific surface area analysis,and tested for mediation of reductive debromination of 1,2-dibromoethane by a green rust reductant under anoxic conditions.A statistical analysis was performed to determine the biochar properties,critical for debromination kinetics and total debromination *** was shown that selected plant based biochars can mediate debromination of 1,2-dibromoethane,that the highest first order rate constant was 0.082/hr,and the highest debromination extent was 27%in reactivity experiments with 0.1μmol(20μmol/L)1,2-dibromoethane,≈22 mmol/L Fe^(Ⅱ)GR,and 0.12 g/L soybean meal biochar(7 days).Contents of Ni,Zn,N,and P,and the relative contribution of quinone surface functional groups were significantly(pbromoethane debromination,while adsorption,specific surface area,and the relative contribution of pyridinic N oxide surface groups were significantly negatively correlated with debromination.

关键词： Environmental remediation biochar Persistent organic pollutants(POPs) Environmental catalysis Green rust

Heat and Mass Transfer Investigation of Hydrocarbon Droplet Evaporation under Rotatory Movement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2005年第11期22卷 2933-2935页

作者： j. Dgheim b. Zeghmati Groupe de Mécanique Acoustique et Instrumentation Centre d'Etudes Fondamentales UPRES EA 2986 Université de Perpignan 52 Avenue de Villeneuve 66860 Perpignan France

The steady-state boundary layer equations of a rotatory movement around hydrocarbon droplets saturated of pure fuel are numerically solved. The transfer equations are schemed by using an implicit finite difference method. The system of algebraic equations is solved by using the Thomas algorithm. The model is compared to the Kreith one and a good agreement is observed between both models. The dimensionless physical parameters of the evaporation phenomena of droplet in rotation are calculated and presented under the effect of the convection.

关键词： Heat and Mass Transfer Investigation of Hydrocarbon Droplet Evaporation under Rotatory Movement

Numerical Analysis of Unsteady Natural Convection Flow and Heat Transfer in the Existence of Lorentz Force in Suddenly Expanded Cavity Using OpenFOAM

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Thermal Science 2020年第6期29卷 1513-1530页

作者： SINGH Ranj.t j. GOHIL Trushar b. Department of Mechanical Engineering Visvesvaraya National Institute of TechnologyNagpur 440010India

The present study reveals the significance of the magnetic field or Lorentz force on the unsteady natural convection flow and heat transfer in the suddenly expanded *** Lorentz force based magnetohydrodynamics(MHD)solver using electric potential formulation coupled with the energy equation by the means of boussinesq approximation is developed in the open-source CFD tool *** unsteady flow is generated by the buoyancy force keeping the Rayleigh number(Ra)at 109,at the fixed Prandtl number(Pr)of *** effects of the magnetic field on the flow and heat transfer are explained for various orientations of magnetic field(bx,b45,and by)in terms of Hartmann number(Ha=0,50,100,300 and 500).The increase in the magnetic field increases the strength of the Lorentz force,which regulates the flow pattern and suppresses down the unsteady nature of flow and heat transfer into the *** is perceived that the average Nusselt number decreases as the intensity of bx and b45 magnetic field ***,for by magnetic field the average Nusselt number increases up to Ha of 100 as compared to the non-MHD case(Ha=0).The distribution of Lorentz force in the domain plays a significant role in the governing of the fluid flow and heat transfer.

关键词： OpenFOAM Lorentz force boussinesq approximation natural convection

Field investigation on effects of railway track geometric parameters on rail wear

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

j.urnal of Zhej.ang University-Science A(Applied Physics & Engineering) 2006年第11期7卷 1846-1855页

作者： SADEGHI j. AKbARI b. School of Railway Engineering Iran University of Science and Technology Narmak Tehran Iran

Rail wear has dramatic impact on track performance, ride quality and maintenance costs. The amount of rail wear is influenced by various elements among which geometric parameters play an important role. The amount of wear in Iran’s railway lines and its imposed maintenance costs oblige us to make modifications on the various geometrical parameters. In order to ensure the effectiveness of these changes, it is necessary to investigate these parameters and their effects on the wear. This research is aimed at studying the effects of different track geometrical parameters on the vertical and lateral wear by conducting a three phase field investigation. The first phase was carried out at the switches of a station, the second phase at a straight line, and the third at a curved line out of the station. The results obtained are analyzed and the role of each track geometrical parameter in the rail wear is discussed. Recommendations for prevention or reduction of rail wear are presented.

关键词： Rail wear Vertical and lateral wear Superelevation Gauge Longitudinal slope Track geometry